Bioactive substance (e.g. drugs, growth factors, nucleic acids etc.) delivery is very important in the biomedical applications which comprise tissue engineering, cell therapy and pharmaceutical therapy. The materials for the delivery carriers must provide biocompatible and biodegradable properties for feasible implantation. Preferably, the material is a fluid ex vivo for easy mixing with drugs and transformation into a gel after being injected into the body by a syringe, catheter or laparoscope for delivering bioactive substances to desired tissue areas. After, the drugs are released over time, achieving therapeutic effects.
There is, therefore, a need for a novel pharmaceutical composition having long-term release and injectability characteristics, in order to effectively make an active agent of a pharmaceutical composition arrive at an affected tissue area.